diff options
| author | Vasiliy Kulikov <segoon@openwall.com> | 2010-11-14 07:06:08 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-11-17 12:27:46 -0800 |
| commit | dda0b38692a7298f433b92b1329867b1ecabb4bb (patch) | |
| tree | 87e070e4d51fe128214c838f534afe1c28178f19 /net/ipv4/tcp_probe.c | |
| parent | 9ea19481db31d614f729f346bdcf28e4e60ff14a (diff) | |
| download | lwn-dda0b38692a7298f433b92b1329867b1ecabb4bb.tar.gz lwn-dda0b38692a7298f433b92b1329867b1ecabb4bb.zip | |
net: ipv4: tcp_probe: cleanup snprintf() use
snprintf() returns number of bytes that were copied if there is no overflow.
This code uses return value as number of copied bytes. Theoretically format
string '%lu.%09lu %pI4:%u %pI4:%u %d %#x %#x %u %u %u %u\n' may be expanded
up to 163 bytes. In reality tv.tv_sec is just few bytes instead of 20, 2 ports
are just 5 bytes each instead of 10, length is 5 bytes instead of 10. The rest
is an unstrusted input. Theoretically if tv_sec is big then copy_to_user() would
overflow tbuf.
tbuf was increased to fit in 163 bytes. snprintf() is used to follow return
value semantic.
Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_probe.c')
| -rw-r--r-- | net/ipv4/tcp_probe.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/net/ipv4/tcp_probe.c b/net/ipv4/tcp_probe.c index 6211e2114173..85ee7eb7e38e 100644 --- a/net/ipv4/tcp_probe.c +++ b/net/ipv4/tcp_probe.c @@ -154,7 +154,7 @@ static int tcpprobe_sprint(char *tbuf, int n) struct timespec tv = ktime_to_timespec(ktime_sub(p->tstamp, tcp_probe.start)); - return snprintf(tbuf, n, + return scnprintf(tbuf, n, "%lu.%09lu %pI4:%u %pI4:%u %d %#x %#x %u %u %u %u\n", (unsigned long) tv.tv_sec, (unsigned long) tv.tv_nsec, @@ -174,7 +174,7 @@ static ssize_t tcpprobe_read(struct file *file, char __user *buf, return -EINVAL; while (cnt < len) { - char tbuf[128]; + char tbuf[164]; int width; /* Wait for data in buffer */ |